Raid 0?

[sean.ferguson]

Ok, the way i understand it is that the RAID0 configuration employs no error checking... at all. So why is it that so many users want to use a SATA-Raid0 setup, if something unfortunate were to happen then the whole drive would require a format surely?
I personally havent setup or configured a system utilising raid, so i have had little need to investigate it much further, however i was wondering if some of the users of Raid here on OSNN could justify just why they dont choose a error-checking system to protect their data.

Is it cost? Is it the difficulty of implementation? i just dont understand.

 

[funky dredd]

It's about speed. If there is no parity then you don't have to write twice, thus speeding up your read times.

 

[Sazar]

exactly... honestly speaking I don't think a striped setup provides the performance boost to compensate for lack of integrity...

some people will still employ +0 for a bigger e-pen0s in their sigs though

I tried mirroring and striping and decided to sod it all... the drivers work fine independently and speed is not such a big thing for me since I am running with CnQ all the time anyways...

 

[sean.ferguson]

see i can understand that if you were running a small lan server and you really really needed speed. But are 7200 or even the 10,000 raptors not fast enough? It seems everything revolvs around benchmarks nowadays

 

[Zedric]

*being picky*
It's faster because you can read and write every other block on each disk.
And it's not the error checking it lacks, it's redundancy. It has just as much error checking as a single drive.
The reason you'd want RAID 0 is because the hdd:s are the slowest component of the computer today (not counting floppies and serial ports which we never use anyway). If you can get the slowest part faster you win a lot. If you get the fastest part faster (the CPU for instance), you don't gain as much since it often has to way for the hdd anyway.

I don't run RAID 0 and I don't want to. I'd like to run RAID 5 though, but that's outside my budget right now...

 

[Heeter]

That's the reason why I switched, Zedric.

Since my gaming machine is a part of my home network, I keep absolutely nothing in the way of files on it. The machine is totally based on giving me the best gaming enjoyment that it can deliver. The HD are the slowest part of the whole setup, I agree. Load times were horrendous, and overall gameplay was noticeably slower. (previous HD: single 60gig8meg7200) I personally think that it was the best investment, financially, that I could of done to improve overall gameplay smoothness. That is more important to me than benchmarks, the enjoyment of my $70CDN each that I pay for the games I play.

Heeter

 

[Steevo]

It takes 4 seconds to load a NFSU level, 6 seconds to load MOH levels.


Why no backup? Cause I have one on a new PC @ work. The only thing I could lose is my new pics, and a few CD's in my collection. I still have the masters, and the pics I plan on uploading to my site one of these days.

@ Heeter, I laid the smack down on some raptors with my Maxtors.

Long live the Quantum!!!!!!!!!!

 

[Son Goku]

Part of what can effect the potential perf benefits of a RAID 0 config I s'pose is the relitive performance of the 2 drives (where they might not be matched). I ran into this when I got my newer Seagate Cheetah. I tried some dif configs (one was a software RAID 0 in win2k). I did fresh installs and ran Adaptec's SCSI Bench 32 each time. Needless to say I got

9.1 GB generation 2 Cheetah - 18.5 GB/sec sustained transfer
37.6 GB generation 3 Cheetah - 35.1 GB/sec sustained transfer
Raid 0 was like 35 GB/sec sustained transfer

Needless to say, I concluded where one drive is significantly faster then the other, RAIDing them as such won't give the perf boost.

There are some things one can do (and of course with SCSI and disconnection the drives don't compete for time on the bus), such as split the swapfile between the 2 drives, and install things accross drives so things can concurently load... I've done that somewhat in tweaking my system. Because the newer drive is about 2x faster then the older, I put about 2/3 of the pagefile on the new drive, 1/3 on the old...

 

[Zedric]

37.6 GB generation 3 Cheetah - 35.1 GB/sec sustained transfer

Wow! Those SCSI:s must be fast. It copies the whole drive in a second?

Needless to say, I concluded where one drive is significantly faster then the other, RAIDing them as such won't give the perf boost.

Yes, plus you'd end up with an array totaling 18 gigs in size, smaller than the big drive.

 

[Zedric]

Since my gaming machine is a part of my home network, I keep absolutely nothing in the way of files on it. The machine is totally based on giving me the best gaming enjoyment that it can deliver. The HD are the slowest part of the whole setup, I agree. Load times were horrendous, and overall gameplay was noticeably slower. (previous HD: single 60gig8meg7200)

Yes, I'm thinking of doing that too. But I'll need a Gbit network and a beefier server before I'll store everything on the server instead of locally.

 

[Steevo]

Yes, plus you'd end up with an array totaling 18 gigs in size, smaller than the big drive.

RAID 0 volume equals the largest partition size of the smallest disk, times the number of drives in teh array.


I can believe 35Mb but not Gb. We used to have a RAID 1 SCSI HP server. Till it was no longer needed.

100Mb+ with 128Kb stripe and onboard RAID. Some people don't like the onboard RAID, to them I say :fu: same problem I had with onboard anything a few years ago. But now it is the norm, and the minimal performance hit you take is offset by the total system speed.

 

[Zedric]

RAID 0 volume equals the largest partition size of the smallest disk, times the number of drives in teh array.

9.1 gigs x 2 drives = 18.2 gigs

What do you mean partition? Partitioning is done after the array is set up. So it's the total size of the smallest drive times the number of drives.

 

[Steevo]

The largest useable volume found in Windows, Linux, OS/400 will be the smallest partition times the number of drives.

I **SHOULD** have a 240Gb RAID array, but the actual reported size is 224Gb, as the RAID controller has it's own way of storing data on the drive. The Windows "format" took about 3 seconds. This is also the reason why you cannot just change RAID controllers without problems.

 

[American Zombie]

Raid 0 will give you better file system benchmarks as noted on this page:
http://www.overclockercafe.com/Articles/RAID/

However, most other performance gains including gaming will be rather insignificant over a single drive as you can see on this page:
http://www.overclockercafe.com/Articles/RAID/pg_2.htm

 

[Zedric]

The largest useable volume found in Windows, Linux, OS/400 will be the smallest partition times the number of drives.

I still don't see what partitions has to do with it.

If you ha said "The largest useable volume found in Windows, Linux, OS/400 will be the smallest drive size times the number of drives." I would have agreed.

 

[toretto]

as performance goes, my main server on my lan has 4 WD 120gb 8mb buffer 7200rpm drives, they are in raid0, it also has 2 wd raptor 74gb drives in it on raid0, the 420gb raid array is for files such as music, images of games, images of movies. the sata's have the OS and all the games installed. I have it all raided for intensely fast load and seek times and fast file transfers among many users.